In a novel technological breakthrough in neural stimulation, our collaborators at Vanderbilt University have developed a new modality that uses low intensity pulsed infrared laser light instead of electrical energy to elicit compound nerve and muscle potentials. Optical stimulation can induce spatially precise, highly controlled and artifact-free action potentials, generated using energies well below tissue ablation threshold, presenting a paradigm shift in neural activation that has major implications to clinical neural stimulation as well as fundamental neurophysiology and neuroscience. This new modality opens the door to such possibilities as high resolution brain mapping and nerve conduction studies as well as high spatial selectivity in neural resection. While optical stimulation has been validated as a viable method for neural activation, to find its way to practical utility and clinical use, a simple, user friendly, portable, reliable and low cost device must be developed. In this proposal, Aculight, in collaboration with Vanderbilt University, plan to demonstrate the utility and unique capability of this concept and develop a portable optical stimulator for routine use in clinical as well as laboratory setting. The specific aims of Phase 1 of the proposed project are as follows; (1) Develop an initial portable 1.85-micron diode laser source for optical stimulation. (2) Assess the feasibility of using the laser for optical neural activation. (3) Evaluate the optimal laser parameters for consistent, damage free neural stimulation, and develop the conceptual design of a second generation laser to match these parameters. The device will be initially developed for the peripheral nerve and will be applied to the central nervous system such as the brain in subsequent phases of the project. At the end of this grant application period, we expect to show the safety and efficacy of the 1.85-um laser for nerve stimulation, and determine the optimal specifications of a commercially viable device that can enter the market of electrical stimulators such as the Grass stimulator in a relatively short time frame for lab and research based neural activation in animal models.